Book excerpt: The convergence of legacy telecommunications towards the Internet and Internet technologies is an ongoing process, resulting in converged Telecom and Internet worlds. Based on current and developing industry practice, this book focuses on the Internet technologies, in particular, on Internet principles, protocols, and services for fixed and mobile networks, including technologies, regulation, and business aspects. This timely resource provides readers with all-around coverage of standardized Internet technologies, Internet standardization regarding the Telecom sector, as well as the convergence of all services onto the Internet. This includes legacy telecommunication services, legacy Internet services, and emerging over-the-top services such as Skype, which appeared during the past decade on a global scale, driven by the penetration of fixed broadband and mobile broadband.